rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): ------------[ cut here ]------------ WARNING: CPU: 1 PID: 8544 at kernel/sched/core.c:3013 rq_unlock kernel/sched/sched.h:1326 [inline] WARNING: CPU: 1 PID: 8544 at kernel/sched/core.c:3013 try_invoke_on_locked_down_task+0x214/0x2c0 kernel/sched/core.c:3019 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 8544 Comm: kworker/1:2 Not tainted 5.9.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events fqdir_work_fn Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 panic+0x2e3/0x75c kernel/panic.c:231 __warn.cold+0x20/0x4a kernel/panic.c:600 report_bug+0x1bd/0x210 lib/bug.c:198 handle_bug+0x38/0x90 arch/x86/kernel/traps.c:234 exc_invalid_op+0x14/0x40 arch/x86/kernel/traps.c:254 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536 RIP: 0010:try_invoke_on_locked_down_task+0x214/0x2c0 kernel/sched/core.c:3013 Code: 45 31 f6 49 39 c0 74 3a 8b 74 24 38 49 8d 78 18 4c 89 04 24 e8 2d 99 08 00 4c 8b 04 24 4c 89 c7 e8 41 53 a5 06 e9 29 ff ff ff <0f> 0b e9 86 fe ff ff 4c 89 ee 48 89 ef 41 ff d4 41 89 c6 e9 11 ff RSP: 0000:ffffc90000da8bd8 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 1ffff920001b517d RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff81612380 RDI: ffff8880a8c66140 RBP: ffff8880a8c66140 R08: 0000000000000033 R09: ffffffff89bcb363 R10: 0000000000001a6e R11: 0000000000000001 R12: ffffffff81612380 R13: ffffc90000da8d00 R14: ffff8880a8c664c0 R15: ffff8880ae736c00 rcu_print_task_stall kernel/rcu/tree_stall.h:267 [inline] print_other_cpu_stall kernel/rcu/tree_stall.h:475 [inline] check_cpu_stall kernel/rcu/tree_stall.h:634 [inline] rcu_pending kernel/rcu/tree.c:3637 [inline] rcu_sched_clock_irq.cold+0x92e/0xccd kernel/rcu/tree.c:2519 update_process_times+0x25/0xa0 kernel/time/timer.c:1710 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176 tick_sched_timer+0x1d1/0x2a0 kernel/time/tick-sched.c:1328 __run_hrtimer kernel/time/hrtimer.c:1524 [inline] __hrtimer_run_queues+0x1d5/0xfc0 kernel/time/hrtimer.c:1588 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1650 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1097 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] sysvec_apic_timer_interrupt+0xb2/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:csd_lock_wait kernel/smp.c:108 [inline] RIP: 0010:smp_call_function_single+0x192/0x4f0 kernel/smp.c:382 Code: 10 8b 7c 24 1c 48 8d 74 24 40 48 89 44 24 50 48 8b 44 24 08 48 89 44 24 58 e8 fa f9 ff ff 41 89 c5 eb 07 e8 20 0a 0b 00 f3 90 <44> 8b 64 24 48 31 ff 41 83 e4 01 44 89 e6 e8 8b 06 0b 00 45 85 e4 RSP: 0000:ffffc90008e57bc0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff920011caf7c RCX: ffffffff81693505 RDX: ffff88809f046400 RSI: ffffffff816934f0 RDI: 0000000000000005 RBP: ffffc90008e57c90 R08: 0000000000000001 R09: ffff8880ae636dc7 R10: 0000000000000000 R11: 0000000000000160 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: ffff8880ae636c00 rcu_barrier+0x29c/0x4a0 kernel/rcu/tree.c:3783 fqdir_work_fn+0x5d/0xf0 net/ipv4/inet_fragment.c:159 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Shutting down cpus with NMI Kernel Offset: disabled Rebooting in 86400 seconds..